Question

Efectuati calculele:
a) ( 3 x+1)(4x-5) -(6x-11)(2x+5)
  b)2x[(-2x ) la a 2 -(x+2 )(x-3)]- 5x(x la a 2 -3)
c)(x+1)[3(x+2)-2 ( x-1)] - 4 (x+2)
d) 4 (2x la a 3 -3 x la a 2 -3x+1 )-2x (x la a 2 -3x+4 )-5(4x la a 3 -6x la a 2 + 6x)
AJUTORR !

Answer 1

a) 12x²-15x+4x-5-(12x²+30x-22x-55)=12x²-11x-5-(12x²+8x-55)
=12x²-11x-5-12x²-8x+55=50-19x
b)2x[4x²-(x²-3x+2x-6)]-5x(x²-3)=2x(4x²-x²+x+6)-5x³+15x
=2x(3x²+x+6)-5x³+15x=6x³+2x²+12x-5x³+15x
=x³+2x²+27x
c)(x+1)(3x+6-2x+2)-4x-8=(x+1)(x+8)-4x-8
=x²+8x+x+8-4x-8=x²+5x
d)8x³-12x²-12x+4-(2x³-6x²+8x)-(20x³-30x²+30x)=8x³-12x²-12x+4-2x³+6x²-8x-(20x³-30x²+30x)
=6x³-6x²-20x+4-(20x³-30x²+30x)=6x³-6x²-20x+4-20x³+30x²-30x
=-14x³+24x²-50x+4